Intel CPU: Core 2 Duo E8400 (3.0 GHz)

Current Cost: $240
Consecutive Guides: New
Price Change: N/A

If you're a little shocked that we're still not using a four-core processor in our Intel configuration, well, we were a bit surprised too. But this comes from the fact that the only "good" Intel quad-core available for under $800 is the G0 stepping Core 2 Quad Q6600, with a rated speed of only 2.40GHz. Our system is built to tolerate overclocking, but we understand that many readers won't do it.

Not that a dual-core will hurt gaming performance, in fact the higher clock speed Core 2 Duo models that fall within our price range assure better gaming than the baseline Q6600 would have provided. Overclockers will appreciate the fact that Core 2 dual-cores can typically be pushed to much higher speeds than quads. This is especially true for this month's choice, the 45nm Core 2 Duo E8400.

Although the 3.0 GHz clock speed remains consistent, the jump from 4MB to 6MB helps the Core 2 Duo E8400 beat our previous Extreme Gaming PC pick, the E6850, in current game and application performance. Added support for SSE4 should also benefit a few yet-to-be-released programs. Lower power consumption will help to keep the finished system cool and quiet, while overclockers can forget the power savings and take advantage of its better overclocking capabilities. Everyone wins, except those who would also like to use their systems for four-core optimized programs, but this is a gaming PC.

Gamers who multitask might still want a four-core processor, and our alternative option remains the G0-stepping Core 2 Quad Q6600. These 2.40GHz parts still have awesome overclocking capabilities, though nothing near the heights achievable with the E8400. Q6600's have used the G0 stepping for several months, so by now all the popular venders should be carrying this stepping exclusively.

AMD CPU: Athlon 64 X2 6400+ Black Edition (3.20 GHz)

Current Cost: $175
Consecutive Guides: New
Price Change: N/A

Not everyone is in agreement over the status of AMD's new Phenom line, but the debate can be narrowed down by the fact that this guide is for an Extreme Gaming PC. The Phenom might beat X2 processors clock-for-clock, but that means little when the clock speed isn't high enough to make up the difference. Our other choice would have been the Phenom 9600 Black Edition, but even overclocking it to 2.60GHz (the practical limit) only brings it up to the gaming performance of the less expensive, stock speed Athlon 64 X2 6400+.

Not that we'd cheap out on the processor for a $4,000 PC. While the Phenom 9600 Black Edition must be overclocked to its limit simply to reach the stock-speed performance of an Athlon 64 X2 6400+, the model we chose is a Black Edition, which could allow it a little extra overclocking room than the base model X2 6400+ we selected in our previous Extreme Gaming PC Buyer's Guide.

Gamers who multitask might still want a quad-core, and the Phenom 9600 Black Edition remains a valid choice while still leaving a great deal of leeway in our budget for other gaming hardware.

CPU Heat Sink: Thermalright IFX-14

Current Cost: $80
Consecutive Guides: New
Price Change: N/A

Few CPU coolers could hope to compete with the Thermalright Ultra 120 Extreme of our previous Extreme Gaming PC buyer's guide, but Thermalright figured out how to take the design to the next level. By increasing the size of its heatsink even more and adding a second sink to cool the back side of the CPU socket, the company created its new cooling monster: The IFX-14.

Attached using only two screws on custom brackets, the IFX-14 fits both Socket AM2 and LGA775 motherboards and can use either 140mm or 120mm fans (not included).

Cooling Fans: Three Scythe S-Flex SFF21E

Current Cost: $45 ($15 each)
Consecutive Guides: 5
Price Change: $0

Originally chosen for its moderate 49CFM airflow at a nearly-silent 20.1 decibels, the Scythe S-Flex SFF21E 1200RPM cooling fan remains our choice for "bare" Thermalright coolers. Two additional fans are added to our list to assist graphics card cooling, and should be used in the lower two side panel locations of the Cooler Master Stacker 830 chassis. The extra airflow is especially useful to overclockers, but anyone not overclocking may wish to forgo the additional $30 expense.